Stabilizer systems for light-curable polyesters

ABSTRACT

A stabilized, U.V. light curable composition comprising a mixture which contains an unsaturated polyester resin, a benzoin ether of a primary or secondary alcohol and, as a stabilizer for the composition, an iron and/or manganese compound soluble in the polyester resin and at least one organic compound having ionically-bound chlorine or capable of forming chlorine ions in situ.

United States Patent [191 Roskott et al. June 25, 1974 'STABILIZER SYSTEMS FOR LIGHT-CURABLE POLYESTERS [56] References Cited [75] Inventors: Lodewijk Roskott, Deventer; UNITED STATES PATENTS Arnoldus Adrianus Maria 3,188,363 6/1965 Amidon et al. 260/4575 C Groenendaal, Vorden, both of 3,627,657 12/1971 Nistri et a]. 204/159.l5 Netherlands [73] Assignee' Akzo N V Arnhem Netherlands Primary Examiner-Murray Tillman Assistant Examiner-Richard B. Turer [22] Filed: Jan. 31, 1973 Attorney, Agent, or FirmStevens, Davis, Miller & [21 Appl. No.: 328,440 MOSher 57 ABSTRACT [30] Foreign Application Priority Data 1 7202217 stabilized, light curable composition compris- Feb. 21, 1972 Netherlands mg a mlxture whlch contains an unsaturated polyester resin, a benzoin ether of a primary or secondary alco- [52] g ggg ggg g hol and, as a stabilizer for the composition, an iron 260/2260/45/ 75- R 260/45 8 260/45 and/or manganese compound soluble in the polyester 6 6 5 260/8'64 resin and at least one organic compound having ioni- H Int Cl 2 /8 6 J 1. 1/1 Cally-bound chlorine or capable of forming chlorine I L 1. ir riqtq ts arcp-t-26 /459;cdzajt vsm 14 Claims, No Drawings STABILIZER SYSTEMS FOR LlGHT-CURABLE POLYFSTERS The present invention relates to a process for preparing a stabilized composition which is curable by U.V. light and which contains unsaturated polyester resin, to the composition per se, and to the curing of this composition. After curing the composition by U.V. light, a polyester resin is obtained suitable for e.g., surfacecoating.

The expression unsaturated polyester resin as used herein means a mixture of an unsaturated polyester and one or more polymerizable ethylenically unsaturated monomers, such as styrene, vinyl toluene, methylmethacrylate, diallyl phthalate, divinyl benzene, p-tert.butylstyrene and vinyl acetate as found in US. Pat. No. 3,367,994.

The weight ratio of monomer to unsaturated polyester generally ranges from 30-50 parts of monomer to 70-50 parts of unsaturated polyester.

The unsaturated polyester may be obtained by reacting a polyhydric alcohol, such as ethylene glycol, propylene glycol, or diethylene glycol, with an unsaturated dibasic carboxylic acid, such as maleic acid, fumaric acid or itaconic acid, if desired in the presence of a saturated acid, such as malonic acid, adipic acid, sebacic acid or tartaric acid, and also phthalic acid, isophthalic acid or tetrachlorophthalic acid.

In order to prevent the unsaturated polyester resin from undergoing premature gelation, a stabilizer is preferably added to the polyester in a quantity of 0.005 percent 0.15 percent by weight, preferably 0.0l percent by weight calculated on the unsaturated polyester. The stabilizers hitherto most used are hydroquinone and p-tert.butyl-catechol.

Unsaturated polyester resins may be cured with the aid of U.V. light. For rapid curing, photo-initiators are incorporated in the unsaturated polyester resin in an amount of 0.1 5 percent, preferably 1 2 percent by weight calculated on the polyester resin. The photoinitiators most used in practice are benzoin ethers of primaryand secondary alcohols, such as methyl alcohol, ethyl alcohol, propyl alcohol, n-butyl alcohol, isobutyl alcohol, 2-ethylhexyl alcohol, propanol-2, butanol-2, pentanol-2 and pentanol-3.

However, unsaturated polyester resins containing as photo-initiators the before-mentioned benzoin ethers, especially those of primary alcohols, have the disadvantage that they gel prematurely on storage in the dark.

It is known that the storage stability of unsaturated polyester resins may be enhanced by incorporating therein quaternary ammonium salts, such as trimethylbenzyl ammonium chloride, trimethylbenzyl ammonium acetate, trimethylphenyl ammonium chloride, trimethylphenyl ammonium phosphate and trimethylphenyl ammonium acetate, in quantities ranging from 0.l to 0.5 percent by weight calculated on the resin.

However, these compounds, when added to polyester resins which contain benzoin ethers as photo-initiators, do not improve the stability or improve the stability only to a small extent.

Surprisingly, it has now been found that the stability of unsaturated polyester resins containing benzoin ethers as photo-initiators may be considerably improved on storage in the dark by incorporating in them an iron and/or manganese compound which is soluble in the resin and at least one organic chlorine compound which either contains ionically-bound chlorine or is capable of forming chlorine ions in situ.

Organic chlorine compounds capable of forming chlorine ions in polyester resins are those compounds which cause a precipitate of silver chloride, when 0.l 1.0 g of the compound is dissolved in'about 10 ml of a mixture of water and acetone, in a ratio of 4:1 to 1:], followed by the addition of about 0.5 ml of 4N nitric acid and a few drops of 0. lN silver nitrate.

Examples of such compounds are compounds having the general formula;

wherein R represents an alkyl group, C C or a substituted or non-substituted aryl group, of C -C, R

represents a substituted or non-substituted aryl group,

C C and R represents a hydrogen atom or an alkyl group, C C,, such as lauroyl chloride, 2- ethylhexanoyl chloride, ortho-methylbenzoyl chloride, benzoyl chloride and cumyl chloride.

Quaternary ammonium chlorides, such as C -C -alkyl-dimethylbenzyl ammonium chloride, C -alkyldimethylethylbenzyl ammonium chloride, phenyltrimethyl ammonium chloride, stearyldimethylbenzyl ammonium chloride, alkylmethylisoquinolinium chloride, C, dialkyldimethyl ammonium chloride, dimethyl-amine.HCl, benzylamine.HCl and triethylamine.HCl may be mentioned as examples of organic compounds which contain ionically-bound chlorine.

The iron and manganese should desirably be incorporated in the polyester resin in the form of a compound which is soluble in the resin. The preferred compounds are soluble manganese or iron salts, such as chlorides, naphthenates, octoates or acetylacetonates.

Dependent upon the nature of the polyester resin and the benzoin ether used, iron and/or manganese compounds are incorporated in the polyester resin in such quantities that the polyester resin contains 0.00002 percent 0.001 percent by weight if iron and/or manganese, preferably 0.0002 percent 0.0004 percent by weight, and 0.001 percent 0.1 percent by weight of organic chlorine compound.

Incorporation may take place in the usual way by dissolving the selected compounds in the unsaturated polyester resin with or without the aid of a solvent. n- Butanol, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, dimethyl formamide, toluene or xylene may be used as a solvent.

However, it is also possible to add the iron and/or manganese salt and the organic chlorine compound to the benzoin ether. In this case, it is advantageous that these compounds are soluble in the benzoin ether. If desired, filters, such as calcium carbonate, calcium magnesium carbonate, magnesium silicate, aluminum silicate, silicon oxide, barium sulphate and calcium sulphate may be added to the polyester resin in an amount of 5 500 percent, preferably 25 250 percent by weight calculated on the polyester resin so as to formulate. it for use as a putty.

In order to prevent air-inhibition, 0.1 percent by weight of a solid paraffin having a melting point of 52 54C. may be added to resins which do not contain fillers.

The composition according to the present invention may be cured in the usual way. To this end, the composition according to the present invention was spread by means of a film drawing knife on a glass plate in layers having a thickness of 300 ,u. Subsequently, these layers were irradiated for 120 sec. with a UV. light source placed 20cm above the resin sheets. The light source had a light emission mainly in the range from 300 to 400 n.m. The curing was determined with an oscillation hardness measuring apparatus according to Persoz. The curing of putties was determined with the aid of the residual styrene-content of the resin cured according to the method described in Kunststoffe, 53 801-804 (1963). The storage stability of the unsaturated resin was determined in the dark at a temperature of 100C.

The following examples illustrate the invention. Where in these examples reference is made to an unsaturated polyester resin, this refers to an all-purpose composition obtained by condensing 1 mol of maleic acid anhydride and 1 mol of phthalic acid anhydride with 1.1 mol of ethylene glycol and 1.1 to 1.2 mol of propane-diol-1,2. The esterification took place at a percent by weight of hexadecyldimethyl ammonium chloride. Subsequently. 2 parts by weight of nbutylether of benzoin were dissolved in the resin. The stability in the dark at 100C and the hardness accord ing to Persoz after lighting for 2 minutes of the composition thus obtained were determined. Comparable tests were made with a polyester resin in which solely the n-butylether of benzoin had been dissolved, and with a polyester resin in which the same ether together with iron chloride or together with the trialkylbenzyl ammonium chloride hereinbefore described had been dissolved. The compositions used and the results obtained are tabulated hereafter (Table 1).

EXAMPLE II In the same way as described in Example I, 0.0004 parts by weight of manganese added in the form of manganese naphthenate, 0.05 parts by weight of trialkylbenzyl ammonium chloride having the composition described in Example I and 2 parts by weight of nbutylether of benzoin were dissolved in 100 parts by weight of the unsaturated polyester resin hereinbefore described. The stability in the dark at 100C. and the hardness according to Persoz after lighting for 2 minm of the. sqmizqsit omt ys absinedwae ter.-

temperature of 200C. while stirring and under a curmined. v I

Table l 2% of 0.0004% of chloro compound stability Persoz Benzoin ether iron as in minutes hardness n-butyl 33 260 n-butyl chloride 36 250 n-butyl 0.05 trialkylbenzyl ammonium 55 266 chloride n-butyl chloride 0.05 trialkylbenzyl ammonium 300 268 chloride n-butyl 0.013 ethylene diamine'HCl 277 n-butyl naphthenate 0.013 ethylene diamine-HCl l 10 278 n-butyl 0.02 cumyl chloride 32 274 n-butyl chloride 0.02 cumyl chloride 290 276 ethyl I 32 284 ethyl naphthenate 40 279 ethyl 0.01 dimethyl amine'HCl 29 289 ethyl naphthenate 0.01 dimethyl amine-HCl 320 291 n-propyl 30 276 n-propyl chloride 270 n-propyl v 0.02 o-methylbenzoyl chloride 34 281 n-propyl chloride 0.02 o-methylbenzoyl chloride 200 289 isopropyl 68 266 isopropyl naphthenate 90 272 isopropyl 0.05 trialkylbenzyl ammonium 1 10 277 chloride isopropyl naphthenate 0.05 trialkylbenzyl ammonium 360 272 chloride rent of nitrogen. After the addition of 0.01 part by weight of hydroquinone to 100 parts by weight of condensate, the latter was mixed with styrene in a ratio of 65 35. The unsaturated polyester resin thus obtained had an acid number of about 50. Y

EXAMPLE I Comparable tests were made with a polyester resin in which solely the n-butylether of benzoin had been dissolved, and with a polyester resin containing in addition to this ether also magnanese naphthenate or trialkylbenzyl ammonium chloride. The compositions used and the results obtained are tabulated hereafter (Table 2).

EXAMPLE III A solution of iron naphthenate in the trialkylbenzyl ammonium chloride described in Example I was dissolved in parts by weight of the unsaturated polyester resin hereinbefore described, so that the polyester resin contained 0.0004 parts by weight of iron and 0.05 parts by weight of trialkylbenzyl ammonium chloride. Subsequently, 2 parts by weight of n-butylether of bena oin were dissolved in the polyester resin and parts by weight of calcium carbonate were mixed in. The stability in the dark at 100C. and the residual styrenecontent after lighting for 2 minutes of the composition thus obtained were determined.

with compositions containing other chlorine compounds applicable according to the invention. The compositions used and the resins obtained are tabulawqhsrsaftqrlkble TABLE 2 2% of 0.0004% of chloro compound stability PCI'SOZ benzoin ether manganese as in minutes hardness n-butyl 33 260 n-butyl naphthenate 255 n-butyl 0r05 trialkylbenzyl ammonium 55 266 chloride n-butyl naphthenate 0.05 trialkylbenzyl ammonium 90 270 chloride TABLE 3 2% of benzoin- 0.0004% of 150% of stability residual styrene n-butyl ether iron as Ca-car- 0.05% of chloro compound in content after chloride bonate minutes lighting for 2 minutes 24 0.24 26 0.22 trialkylbenzyl ammonium chloride 34 0.20 trialkylbenzyl ammonium chloride 47 0.23 phenyltrimethyl ammonium chloride 35 0.19- phenyltrimethyl ammonium chloride 49 0.19 stearyldimethylbenzyl ammonium chloride 31 0.24 stearyldimethylbenzyl ammonium chloride 44 0121 a1kylmethylisoquinoliniumchloride .27 0.22 alkylmethylisoquinoliniumchloride 41 0.18 dialkyldimethyl ammonium chloride 27 0.22 dialkyldimethyl ammonium chloride 43 0.21

mixture of 25% of dodecylmethylisoquinolinium chloride 55% of tetradecylmethylisoquinolinium chloride 17% of hexadecylmethylisoquinolinium chloride 3% of octodecylmethylisoquinolinium chloride mixture of 2% of di-tetradecyldimethyl ammonium chloride 38% of di-hexadecyldimethyl ammonium chloride 60% of di-octodecyldimethyl ammonium chloride EXAMPLE lV Comparable tests were made with a composition containing n-butylether of benzoin and calcium carbonate, with a composition containing in addition iron chloride In an analogous way to that described in Example 111, comparable tests were made with other compositions,

and with a composition which contained in addition to 40 as described in Tables 4 and 5. The results obtained n-butylether of benzoin, trialkylhenzyl ammonium chloride. Analogous and comparable tests were made these tables.

with these compositions have also been mentioned in TABLE 4 2% of benzoin- 0.0004% of 0.05% of alkyldimethylstability residual styrene n-butyl ether manganese as filler benzyl ammonium in content after naphthenate chloride minutes lighting for 2 minutes i 150 Cacarbonate 27 0.23 150 Ca-carbonate 43 0.20 Al-silicate 16 0.21 50 Al-silicate 44 0.20 7

mixture of 5% of dodecyldimethylbenz'yl ammonium chloride of tetradecyldimethylbenzyl ammonium chloride 30% of hexadecyldimethylbenzyl ammonium chloride 5% of octodecyldimethylbenayl ammonium chloride TABLE 5 2% of benzoin 0.0004% of I stability residual styrene ether iron as filler chloro compound in minutes content after chloride lighting for 2 minutes isopropyl Ca-carhonate 36 0.18 isopropyl 150 Cll-Cfil'bOllfllE 39 0.17 isopropyl 150 Ca-carhonate 0.05 dialkyldimethylammonium 46 0.20

chloride isopropyl 150 Cu-curhonute 0.05 dialkyldimethylummonium 61 0.19

chlorldti 38% of di-hexadecyldimethylammonium chloride 9.9% i fli i lfi fflf l'BEPY'F QMEK93H? What is claimed is:

1. A process for preparing a stabilized, UV. light curable composition comprising forming a mixture con-- taining 0.1-5 percent by weight of a benzoin ether of a primary or secondary alcohol, as a stabilizer 000002-0001 percent by weight of a soluble iron and-' /or manganese compound and 0001-01 percent by weight of at least one organic chloro compound selected from the group consisting of (a) quaternary ammonium chlorides, (b) amine hydrochlorides and compounds capable of forming chlorine ions in situ and the remainder an unsaturated polyester resin, said percentages by weight being calculated on the polyester resin.

2. The process according to claim 1, in which the benzoin ether of a primary or secondary alcohol is incorporated in the composition in an amount of l 2 percent by weight calculated on the polyester resin.

3. The process according to claim 1, in which the iron or manganese compound is incorporated in the composition in an amount of 0.0002 0.0004 percent by weight calculated on the polyester resin.

4. The process according to claim 3, wherein the iron and/or manganeseis incorporated in the composition as a chloride, naphthenate, octoate or acetylacetonate.

5. The process according to claim 1, in which the organic chloro compound is a quaternary ammonium mp nd;

TABLE 5 2% of benzoin 0.0004% of stability residual styrene ether iron as filler chloro compound in minutes content after chloride lighting for 2 minutes n-butyl 50 Al-silicate 12 0.20 nbutyl 50 Al-silicate l8 0.18 n -butyl 5O Al-silicate 0.05 alkyldimethylbenzylamrn. 27 0.18

chloride n-butyl 50 Al-silicate 0.05 alkyldimethylbenzylamm. 46 0. l9

chloride n-butyl 50 Al-silicate 0.05 phenyltrimethylammonium 0.20

chloride n-butyl 50 Al-silicate 0.05 phenyltrimethylammonium 48 (H8 chloride mixture of 2% of di-tetradecyldimethylammonium chloride 38% of di-hexadecyldimethylammonium chloride 60% of di-octodecyldimethylammonium chloride mixture of 5% of dodecyldimethylbenzylammonium chloride 60% of tetradecyldimethylbenzylammonium chloride of hexadecyldimethylbenzylammonium chloride 5% of octodecyldimethylbenzylammonium chloride n-butyl 50 Al-silicate 0.05 stearyldimethylbenzylamm. 25 0.20

chloride n-butyl 50 Al-silicate 0.05 stearyldimethylbenzylamm. 43 0.20

chloride 'n-butyl 50 Al-silicate 0.05 alkylmethylisoquinolinium 25 0.21

- chloride n-butyl 50 Al-silicate 0.05 alkylmethylisoquinolinium 43 0,18 chloride 1 n-butyl 50 Al-silicate 0.05 dialkyldimethylammonium 28 0.22

chloride n-butyl 50 Al-silicate 0.05 dialkyldimethylammonium 46 0.19

' chloride v isopropyl 50 Al-silicate 43 0.17 isopropyl 50 Al-silicate 45 0.15 isopropyl Alsilicate 0.05 dlilzilkytlldimethylammonium 54 0.19

c on isopropyl 50 Al-silicate 0.05 dialkyldimethylammonium 82 0.l7

chloride mixture of 25% of dodecylmethylisoquinolinium chloride 55% of t'etradecylmethylisoquinolinium chloride l7% of hexadecylmethylisoquinolinium chloride 3% of octodecylmethylisoquinoliniumchloride mixture of 2% of di-tetradecyldimethylammonium chloride 6. The process according to claim 1, in which the organic compound capable of forming chlorine ions in gig; is a compound having the general formula:

0 CH: R-t or 31-0-01 01 R:

tion a filler is incorporated in the composition in an amount of 5 500 percent by weight calculated on the polyester resin. I

8. The process according to claim 7, in which the amount of filler is 25 250 percent by weight. 9. A composition curable by UV. light comprising 0.1-5 percent by weight of a benzoin ether of a primary or secondary alcohol, as a stabilizer 000002-0001 percent by weight of a soluble iron and/or manganese compound and 0001-01 percent by weight of at least one organic chloro compound'selected from the group consisting of (a) quarternary ammonium chlorides, b) amine hydrochlorides and (c) compounds capable of forming chlorine ions in situ and the remainder an unsaturated polyester resin, said percentages by weight being calculated on the polyester resin.

10. The composition as claimed in claim 9, in which the iron or manganese compound is a chloride, naphthenate, octoate or acetyl acetonate.

11. The composition as claimed in claim 9, which includes a quaternary ammonium compound.

12. The composition as claimed in claim 9, which includes a compound having the general formula:

tion as claimed in claim 9. 

2. The process according to claim 1, in which the benzoin ether of a primary or secondary alcohol is incorporated in the composition in an amount of 1 - 2 percent by weight calculated on the polyester resin.
 3. The process according to claim 1, in which the iron or manganese compound is incorporated in the composition in an amount of 0.0002 - 0.0004 percent by weight calculated on the polyester resin.
 4. The process according to claim 3, wherein the iron and/or manganese is incorporated in the composition as a chloride, naphthenate, octoate or acetylacetonate.
 5. The process according to claim 1, in which the organic chloro compound is a quaternary ammonium compound.
 6. The process according to claim 1, in which the organic compound capable of forming chlorine ions in situ is a compound having the general formula:
 7. The process according to claim 1, in which in addition a filler is incorporated in the composition in an amount of 5 - 500 percent by weight calculated on the polyester resin.
 8. The process according to claim 7, in which the amount of filler is 25 - 250 percent by weight.
 9. A composition curable by U.V. light comprising 0.1-5 percent by weight of a benzoin ether of a primary or secondary alcohol, as a stabilizer 0.00002-0.001 percent by weight of a soluble iron and/or manganese compound and 0.001-0.1 percent by weight of at least one organic chloro compound selected from the group consisting of (a) quarternary ammonium chlorides, (b) amine hydrochlorides and (c) compounds capable of forming chlorine ions in situ and the remainder an unsaturated polyester resin, said percentages by weight being calculated on the polyester resin.
 10. The composition as claimed in claim 9, in which the iron or manganese compound is a chloride, naphthenate, octoate or acetyl acetonate.
 11. The composition as claimed in claim 9, which includes a quaternary ammonium compound.
 12. The composition as claimed in claim 9, which includes a compound having the general formula:
 13. The composition of claim 9, which includes in addition a filler in an amount of 5 - 500 percent by weight calculated on the polyester resin.
 14. The process for curing an uNsaturated polyester resin comprising irradiating with U.V. light a composition as claimed in claim
 9. 